Research progress on interdiffusion behavior at interface between high-temperature protective coatings and single-crystal superalloys

Interdiffusion behavior at the interface between high-temperature protective coatings and single-crystal su⁃ peralloys is a critical issue affecting the service life and reliability of aircraft engine turbine blades. With the continuous increase in turbine inlet temperatures of aircraft engines，the elemental interdiffusion between coatings and single-crystal superalloys has become particularly serious. This article systematically reviews the interdiffusion process be⁃ tween high-temperature protective coating and single-crystal superalloys systems，clarifying the formation mechanisms of the Interdiffusion Zone（IDZ），Substrate Diffusion Zone（SDZ），and Secondary Reaction Zone（SRZ）. The influ⁃ encing factors and laws of the interdiffusion behavior and mechanical properties of coatings/single-crystal superalloys are explored from the perspectives of single-crystal composition，orientation，thermal-mechanical coupling environ⁃ ment，and thin-wall effect of single-crystal superalloys. Additionally，this work reviews recent research advances and identifies persistent challenges associated with interface control methodologies for diverse coating systems and single-crystal superalloys，and proposes targeted design strategies along with prospective directions for future development.